Ballcocks again

[malbro]

evening all hope someone can help a complete fish out of water.
in my loft i have 3 tanks. 1 cold 1 that feeds the hot water tank and 1 that feeds the heating system.
The central heating tank overflow drips intermittantly sometimes nothing for a week then it drips constantly and although i have lowered the level in the tank and marked it. Yes i actually sat for an hour in the loft and no drips into the tank occured yet next day the level had risen and it was dripping again.
The only other way water could get in is backfeeding into the bottom of the tank ??? could this be possible water coming back through the pump???? or am i missing something regarding the ballcock.
Awaits replies with wellies at the ready
edit what is the minimum level i can reduce the water to as its actually set quite high ( 20mm from the overflow level)

 

[Winston]

The F&E tank doesnt need to be that high, change the ballfloat valve and observe, you may have a leak in the HWC.

 

[malbro]

The F&E tank doesnt need to be that high, change the ballfloat valve and observe, you may have a leak in the HWC.

would it be ok set half way ?? say 300mm ??
i plan to get a new ballcock this week is that the same as the ballfloat valve? should i be changing both sides ie the float and the outer connection ??

cheers Winston

 

[secret squirrel]

ballcocks to you as well....... ha ha!

When I'm setting a ball cock in the f & E tank I try and set about 3 cm above the outlet. Thats about 1.5 inches. Your covering the hole and a bit more just to prevent air getting in.

Change the ball cock but proving the connection is good and not leaking no need to change it.

If it continues to overflow you have another problem

You should have an isolation valve on it. This is a requirement but makes a lot of sense. If your draining down you can turn the water off there and not to the whole house. I like to use full bore quarter turn valves on them. Just easier to use.

 

[malbro]

ballcocks to you as well....... ha ha!

When I'm setting a ball cock in the f & E tank I try and set about 3 cm above the outlet. Thats about 1.5 inches. Your covering the hole and a bit more just to prevent air getting in.

Change the ball cock but proving the connection is good and not leaking no need to change it.

If it continues to overflow you have another problem

You should have an isolation valve on it. This is a requirement but makes a lot of sense. If your draining down you can turn the water off there and not to the whole house. I like to use full bore quarter turn valves on them. Just easier to use.

i set it at around 20-25 mm below the overflow yet it still managed to fill and overflow.

 

[REDSAW]

i set it at around 20-25 mm below the overflow yet it still managed to fill and overflow.

thats because the water expands up into the tank, doh!.
set it to around 3'' from bottom of tank to water level cold.

 

[malbro]

thats because the water expands up into the tank, doh!.
set it to around 3'' from bottom of tank to water level cold.

cheers will do ta

 

[Plumbstar Tom]

yeh, you only need to cover the feed to the system with a bit of give

as above 1and a hlaf inches is plenty

Doesn't sound like you need a need ball valve as it didn't drip from there when you watched it

Wont hurt to replace it if its old but most systems with 3 tanks in the loft i have found to not be too old

 

[malbro]

yeh, you only need to cover the feed to the system with a bit of give

as above 1and a hlaf inches is plenty

Doesn't sound like you need a need ball valve as it didn't drip from there when you watched it

Wont hurt to replace it if its old but most systems with 3 tanks in the loft i have found to not be too old

correct its the newest tank up there by a country mile. will empty it out to around 3''
maybe another daft question but what does the tank actuall feed ? the rads etc ??

 

[secret squirrel]

I won't go into too much detail because I'll end up confusing myself and giving myself a migraine, it goes into the primary return on the cylinder (two pipes sticking out of the side of your cylinder, bottom one) at some point. This in turn goes back to the boiler for re-heating.

 

[Plumbstar Tom]

its only for expansion really